How to Get Rid of Smelly Drains for Good

A whiff of sewer or rotten egg every time you walk past the sink is more than unpleasant, it is usually your drain telling you something is building up. The good news is most smelly drains are an easy DIY fix. Here is what causes the smell and how to get rid of it, plus the cases where the odour points to a bigger problem.

Why your drain smells

There are really only a few causes:

• Biofilm build-up. A slimy layer of soap, grease, hair and food gradually coats the inside of the pipe. Bacteria feed on it and give off that musty, eggy smell. This is the most common cause by far.
• A dry trap. Every drain has a U-bend (the trap) that holds a little water to block sewer gas from coming back up. In a rarely-used shower, basin or floor waste, that water evaporates and the gas comes straight through.
• Trapped food or grease, especially in kitchen sinks.
• A partial blockage further down, where waste sits and rots instead of flowing away.

How to get rid of a smelly drain

Work through these in order:

1. Clean what you can reach. Pull the plug, clear the hair and gunk from the strainer and the top of the waste.
2. Flush with hot water. A kettle of hot water (not boiling, if you have PVC pipes) washes out loose grease.
3. Bicarb and vinegar. Pour half a cup of bicarb soda down the drain, then half a cup of white vinegar. Let it fizz for fifteen minutes, then flush with hot water. This breaks down the biofilm that causes the smell, and it is far kinder to your pipes than caustic drain cleaners.
4. Refill a dry trap. If it is a drain you rarely use, just run the tap for thirty seconds, or tip a jug of water down a floor waste. A splash of cooking oil on top slows evaporation.

Do that and most smells are gone the same day.

Kitchen smells are a bit different

Kitchen drains smell because of fat, oil and grease that has cooled and stuck to the pipe. Hot water and dish soap, or bicarb and vinegar, will shift the early build-up. The long-term fix is to stop pouring fats down the sink in the first place, let them set and bin them instead.

When the smell means something bigger

Call a plumber if:

• The smell keeps coming back within days no matter how well you clean.
• More than one drain smells at once, which points to a problem in the shared line, not one fixture.
• You also have slow drainage or gurgling, classic signs the drain is partly blocked. See our guide on how to clear a blocked drain.
• There is a persistent sewer smell through the house, which can mean a cracked pipe or a venting problem.

A recurring smell usually means waste is sitting in the line, often from roots or a damaged pipe. We can camera the line to find it and clear it properly with a high-pressure jetter. If you are in Newcastle and the smell will not budge, give us a call, we will find what is feeding it.